Double-chamber back-filling apparatus with automatic control



NOV. 6, 1934. DOMlNA 1,979,320

DOUBLE CHAMBER BACK FILLING APPARATUS WITH AUTOMATIC CONTROL Filed Aug. 25. 1932 5 Sheets-Sheet l INVENTOR I fiearg fiamma ATTORNEY NOV. 6, 1934. l G, DOMlNA 1,979,320'

DOUBLE CHAMBER BACK FILLING APPARATUS WITH AUTOMATIC CONTROL Filed Aug. 25, 1932 5 Sheets-Sheet "2 A; ATTORNEY G. DOMINA Nov. 6, 1934.

DOUBLE CHAMBER BACK FILLING APPARATUS WITH AUTOMATIC CONTROL 5 Shets-Sheet 3 Filed Aug. 25, 1932 Q INVENTOR Georg flaming BY Q; Q.

A ATTORNEY Nov. 6, 1934.

cs. DOMINA 1,979,320

DOUBLE CHAMBER BACK FILLING APPARATUS WITH. AUTOMATIC CONTRQL ILJI Filed Au 25, 1932 s Sheets-Sheet 4 INVENTOR Georg flom'zna ATTORNEY ONTROL G. DOMINA Nov. 6, 1934.

DOUBLE CHAMBER BACK FILLING APPARATUS WITH AUTOMATIC C 5 Sheets-Sheet 5 Filed Aug; 25, 1932 as a2 M ATTORNEY Patented Nov. 6, 1934 UNITED STATES PArsNr clerics Georg Domina, Berlin, Germany, assignor to Cement-Gun Company, Inc., a corporation of New York Application August 25, 1932, Serial No. 630,419

7 Claims.

The present invention relates to doublechamber charging means for apparatus in which loose material supplied through the charging means is transported by compressed iiuid, such as compressed air, to any desired point where it may be packed tightly if suitably confined, and relates more particularly to apparatus of the class referred to which is adapted, for example, for backfilling in mines, and in which there is an 10 automatic control of the admission of loose material to the first chamber and of the passage of the material from the first chamber to the second chamber.

In double-chamber charging devices of the class referred to, the two chambers are preferably arranged one above the other and are pro- Vicled with an airtight closure at the top of the upper chamber and an airtight closure between the chambers so that one at least of the closures may be closed at all times during the operation, thus preventing undue loss of compressed air. Assuming that both of the closures are closed and that it is desired to admit material to the upper chamber, the air in the upper chamher is released, the closure. at its top is opened, material is dropped, into the chamber and the top of the chamber is again closed. Then the air pressure in the upper chamber may be brought up to that in the lower chamber, and

the closure between the two chambers may be opened to permit the material in the upper chamber to pass down into the lower chamber and then closed again preparatory to starting another cycle of operation.

l leretofore, the control of the opening and closing of the closures or valves andof the pressure in the upper chamber was effected by hand. and the proper operation of the various parts of the charging apparatus in proper sequence and timing depended to a high degree upon the skill and attention of the workmen in charge. Especial care and attention were therefore necessary because errors in performing the operations in the proper sequence and timing led not only to loss oi compressed air but gave rise to material interruptions of operation.

An important object of the invention is to provide improved apparatus of the general class to which reference has been made. Another object is to provide apparatus by which the above mentioned and other disadvantages of apparatus heretofore in use will be avoided. Further objects relate to features and details of the automatic control.

According to a preferred embodiment of the the lower chamber.

01. sea-55) invention, it is applied to apparatus of the general class described in which the closures or valves at the tops of the upper and lower chambers include closing members or slides which are moved in a generally horizontal direction into 0 and out of their closing positions. With this class of closures, the slide members after movement horizontally to closing position are lifted by suitable means, operated by compressed air, for example, into sealing position where they will be subjected to the upward pressure of compressed air in the chambers below the same. Preferably the doub1e-chamber charging apparatus is provided beneath the lower chamber with a feed wheel which receives material from the lower chamber and discharges it into a discharge line through which it is carried by a strong current of compressed air to any desired point. Preferably also the feed Wheel is oper ated by an air motor driven by compressed air from the same supply as the compressed air of the discharge line and this air motor is used to operate a control device whereby compressed air is utilized to control the movement of the slides to and from closing position and to sealing posi- 89 tion and tocontrol the air pressure in the two chambers. Such control. of air pressure may involve connecting the upper chamber with the outside atmosphere before moving the slide to open position and connecting the lower chamher with the upper one, after closing the upper slide, to equalize the pressures in the two chambers before opening. the lower side to permit passage of material in the upper chamber into It will be seenthat the apparatus just referred to in general terms will be entirely automatic and independent of the attention of the operator except for the supply of, material at the top of the upper chamber. The invention also possesses a further special advantage in that the operation of ,thecontrol device and the feeding of the material itself are effected by the same medium, for example, a compressed air motor. As a result of use of such an elastic driving means for all parts of the apparatus interfer ence with the operation in any part of the system, for example, clogging of the feed line, will automatically produce an increase in pressure in the entire system and thereby either produce a corresponding slowing up, a stoppage in extreme cases or, when the normal load is not reached, a corresponding acceleration of operation as a result of the pressure difierence produced. The fluctuations of pressure ratios in the currents 110 of compressed. air resulting from changes of load may be used for the actuation of signal devices or suitable control devices.

Other objects and advantages will appear upon consideration of the following detailed description and of the drawings, in which Fig. 1 is a view in elevation illustrating a preferred embodiment of the invention applied to a double-chamber backfilling device;

Fig. 2 is a partial vertical section taken along line 22 of Fig.

Fig. 3 is a fragmentary sectional view, taken along the line 3-3 of Fig. 5;

Fig. 4 is a vertical section taken along the line 4-4 of Fig. 5;

Fig. 5 is a top plan view of the apparatus shown in Fig. 1, certain parts being omitted;

Fig. 6 is a view of the outer surface of the distributing sleeve of the automatic control device developed on a plane surface;

Fig. 7 is an axial section of the control device;

Fig. 8 is a horizontal section taken along the line 88 of Fig. 7;

Fig. 9 is a horizontal section taken along the line 9-9 of Fig. 7; and

Fig. 10 is an axial section of the rotary member of the automatic device taken at right angles to the section in Fig. '7.

Referring to the drawings, reference numerals 10 and 11 designate the casings of the upper and lower chambers respectively. These casings may be of the same size and shape in most respects but the lower casing 11 is provided at its side near its lower edge with an opening 12 through which compressed air or the like is supplied from. a compressed air line 13, preferably provided with a flange 14 to facilitate connection with the lower casing 11. Each of the casings or casing sections 10 and 11 is provided at the lower edge of a cylindrical body portion with a flange 15, the flange 15 of the lower casing cooperating with a flange 16 on an upward projection 17 of a base 18 and the flange 15 of the upper casing resting on a correspondingly shaped part on the upper end of the lower casing 11. Preferably gaskets 18a are used to effect a tight seal between the parts which are secured together in any suitable manner. Preferably also each of the casings is provided at its top with an annular flange 19 extending inwardly and slightly downwardly and, among its different uses, serving to support a funnel 20 with a lower end of sufficient size to prevent passage thereof through the opening of the corresponding annular flange 19 and an upper end of such diameter as to fit into the cylindrical portion of one of said casings or casing sections. Of course there is no chamber above the chamber 10 but the upper funnel 20 may fit into a cylindrical member 21 resting on the top of the casing 10 and being of suflicient height to enclose the upper end of such funnel.

Mounted in the cylindrical portion 17 of the base 18 is a feed wheel 22 having a hollow hub 23 and radial blades 24 providing pockets therebetween into which drop portions of material from the lower casing 11, which portions are then carried around to a position beneath air inlet opening 12 so that the material will be blown out of the pocket through outlet sections 26 and 27. The deflection of the air from the inlet 12 downwardly toward the outlet may be obtained by means of a deflector 24a (Fig. 2). Section 26 is preferably in the form of a liner for a portion 28 of the base 18 and is held therein by means of a plate 29 having an opening therein to register with the end of the outlet portion 26 and being of sufficient size to cooperate for fastening purposes with a flange 30a on the base portion 28. An air tight connection between the plate 29 and the flange 30a may conveniently be obtained by the use of a suitable washer 31. The discharge member 27 registers with the opening in the plate 29 and may be secured to the plate in any suitable manner.

The hub 23 of the feed wheel 22 may be made up of a cylindrical portion from which the blades 24 project and, at the top of said cylindrical portion, a frusto-conical part provided at its top with a downwardly extending sleeve 31a mounted on the upper end of an actuating shaft 30 which in turn is mounted in an upwardly projecting sleeve 31b supported by the bottom 32 of said cylindrical portion 17 of the base. Preferably the arrangement is such that the wear at the bottom and outer sides of the feed wheel as the latter is revolved is received by a replaceable liner 33 having an upright cylindrical portion and an annular bottom portion provided with an opening at the discharge side of the machine through which the discharge takes place.

In the operation of the machine, material may be admitted to the upper casing or chamber while the upper end of the lower chamber or casing is closed and material from the upper chamber may be supplied to the lower chamber while the upper end of the upper chamber is closed. In this way undue loss of compressed air and blowing of material upwardly through the apparatus are avoided. Obviously the sealing of the openings at the upper ends of the two casings may be effected in different ways. It has however, been found desirable to use for this purpose sealing means in which a closure member or slide is moved horizontally to and from its closing position in a plane somewhat below its sealing position and, when moved to its closing position, is raised to its sealing position where it will be subjected to the pressure in the chamber beneath the same.

As illustrated for the upper chamber the sealing is effected by means of a sealing member or plate 35 which when raised to its sealing position engages an annular ring or washer 36 of suitable material, such as rubber. Preferably the annular washer 36 has a cross-section in the general shape of a keystone or wedge and the inner side of the ring or washer engages a secondary flange 37 projecting downwardly from the inwardly projecting main flange 19 and is engaged at its outer edge by a strip 38 secured to the flange 19 in any suitable manner.

For horizontal movement toward and from closing position, the sealing member 35 is mounted on an arm 39 pivotally mounted in the upper and lower walls of an extension 40 of suitable shape to accommodate the plate 35 and arm 39 when the plate 35 is moved to open position. At its pivot end, the arm 39 is provided with a vertical shaft 41 rigidly connected therewith for the purpose of actuating the same. The shaft ll has a practically air tight mounting in the top and bottom Walls of the extension 40 and at its top is provided with an arm 4' pivotally, and preferably adjustably, connected with a piston rod 43 provided with a piston 44 in a cylinder 45 having an end 46 through which the piston rod 43 passes and a head end 4'7 pivotally connected with a fixed lower chamber.

bracket 48 projecting from the upper part of said extension 40. Air maybe admitted through a suitable conduit 49 to the head end of the cylinder to swing the plate to open position or through a conduit 50 to the piston-rod end of the cylinder to return the plate to closed position; i I l The vertical movement of the closure plate 35 with reference to the arm 39 is very slight and the lifting of the plate may be provided for by securing to the plate at its lower side a diaphragm 52 connected at its outer edge with an annular downward projection 54 from the plate 35. The diaphragm rests on the end of the arm 39 which is arranged with a shallow chamber beneath a central downward projection 53 on the plate 35 and engages the diaphragm 52 between the downward projections 53 and 54 of the plate 35. Air may be supplied to the shallow chamber 55 through a vertical bore 56, a bore 57 extending along the arm 39 to its pivotal axis and a bore 58 extending downwardly through the lower end of the shaft 41 where it communicates with a pipe or duct 59. It will be evident that admission of compressed air through the pipe 59 will cause the plate 35 to be lifted to scaling position. The lower limit of movement of the plate 35 may be determined by one or more set screws 60 extending upward- 1y through the swinging end of the arm 39 and through the diaphragm to engage the lower surface of the plate 35 when the latter is in depressed position. The set screw 60 serves to maintain the proper relation between the plate j 3.: and the arm 35 when the latter is swung about the verticalaxis. i l

The foregoing description of the opening and closing of the closure or valve at the upper end of a chamber was directed more particularly to the device at the upper part of the upper chamber. The corresponding devices at the upper part of the lower chamber are substantially the same as those described and for convenience in distinguishing between the two sets, particularly in connection with description of operation, the reference numerals applied to the lower set are the same as those used for the upper set except for the addition of the letter a.

The apparatus which has just been described is in general similar to apparatus heretofore in use in which the supply of air to the ends of a slide-operating cylinder and to the lower side of a diaphragm for lifting a slide to sealing position, is controlled manually. Also in such machines heretofore in use the exhausting of the air from the upper chamber is controlled manually and the same is true in regard to the supplying of compressed air to the upper chamber to bring it up to the same pressure as the According to the present invention, manual control of these operations is dispensed with and provision made for automatic control.

Heretofore the feed wheels in apparatus of this kind have commonly been operated by use of an air motor receiving its supply of air from the same source as the supply line 13 through which is supplied the air to drive the material out of the pockets of the feed wheel and to transport it through a suitable discharge line to any desired point. According to the illustrated embodiment of the invention, use is made an air motor 61 to drive the feed wheel 22 and to operate an automatic control device 62. To this end, the vertical shaft 63 of the air motor is provided near its lower end with a gear 64 from which power is transmitted through gears 65 and 66 to a gear 6'7 mounted on the shaft 30 for driving the same. The shaft 63 is also provided with a pinion 68 which acts through a gear 69 to drive a gear 70. Projecting upwardly from the gear 70 is a pin 71 which engages an arm '72 mounted to turn about the same axis as the gear '70 and carrying a pawl '73 which is pressed by a spring 73a against a ratchet wheel 74. The ratchet wheel '74 is connected with a gear 75' through which it acts to drive a gear '16 fixed on a shaft 77 projecting downwardly from a rotating member or rotor 76 of the control device 62. The gears in the driving train for the rotor 78 of the control device are so arranged as to produce a considerable reduction in speed of rotation and the pawl-and-ratchet connection in this train provides for a one way drive of the rotor '78 and prevents rotation of the rotor '78 in the wrong direction. The base 18 includes a substantially horizontal portion extending over the gear trains just described and having seats to receive the lower ends of the motor 61' and control device 62. Beneath the gear trains is a member '79 which is more or less in the nature of a pan and forms the lower part of a compartment containing the two gear trains, being fastened to the horizontal portion of frame 18 in any suitable manner. The gears 69 and 70 are mounted directly on the pan 79 which also supports the gears 65 and 66. Beneath the pinion or gear 68, there is an opening 30 which is normally closed by a closure member 81.

The control device 62 includes a cylindrical outer casing 82 having outwardly projecting flanges 83 and 84, respectively, at its upper and lower ends. The cylindrical casing 82 is provided near the upper flange 83 with six ports in the same horizontal plane arranged in two groups, three ports, 85, 86 and 87 being in one group and the other ports 88, 89 and 90 being in the other (see Fig. 8). As indicated in Fig. 1, port 85 is connected by means of duct 50 with the piston rod end of the upper cylinder 45, port 86 is connected by the duct 59 with the interior of the upper slide-supporting arm 39, port 87 is connected by the duct 49a with the head end of the lower cylinder 54a, port 88 is connected by the duct 50:: with the piston rod end of the lower cylinder 45a, port 89 is connected by the duct 59a with the interior of the lower slidesupporting arm 39a, and port 90 is connected by the duct 49 with the head end of the upper cylinder 45.

Beneath the ports 85 and 86 and at a lower level is a port 91 connected by a duct 92 with the lower end of a cylinder 93 forming the lower part of a member 94 having an upper part 95 of greater diameter than the cylinder 93 and being provided at one side with an openingwith which. is connected the end of a pipe line or duct 96 opening into the atmosphere. The upper end of the member 94 is secured in engagement with the bottom of the extension 40 of the upper chamber, in axial alignment with an opening 97 of smaller diameter than the interior of the upper part 95 of the member 94,

so that there is an annular, downwardlydacing shoulder 98 which as brought out hereinafter may be used as a valve seat. The cylinder 93 and the cylindrical upper part 95 of the member 94 are provided with pistons 99 and 166, re-

spectively, so connected with each other that .ee

when the piston 99 is at the upper end of cylinder 93 a washer on the top of the piston 100 will engage the valve seat 98 and prevent communication between the upper chamber and the atmosphere, and when the piston 99 is at the lower end of the cylinder 93 there will be communication between the upper chamber and the atmosphere. It will be seen that the structure just described includes a venting device which may be closed by compressed air admitted through the duct 92. Preferably provision is made of a tube projecting upwardly from the opening 97 to guard against the passage of back filling material from the upper chamber through the opening. 97.

At a still lower level than the port 91 and between the ports 88 and 89, is a port 101 connected by a duct 92a with a cylinder 93a forming part of a venting device for the lower chamber similar to the corresponding device associated with the upper chamber, the only difference being that the pipe line or duct 96a is connected with the interior of the upper chamber. Near the base of the casing 82, there are provided two opposite ports 102 and 103 through either one of which air may be supplied to the interior of the casing. According to the illustrated arrangement the port 103 is closed in any suitable manner and air is supplied to the port 102 through a duct 104 connected with the main air supply pipe 13 at the supply side of a valve 105 in said pipe 13. This duct 104 may also be used to supply compressed air to the air motor 61 and for this purpose may be connected with the air motor by means of a branch line 106 provided with a manually operable control valve 107.

Inside the casing 82 is a normally stationary sleeve 108 provided with ports and passages through which compressed air passes to the outlet ports in the casing 82 Viewed from the outside as illustrated in Fig. 6, the sleeve 108 is provided with ports 85a, 86a, 87a, 88a, 89a and 90a substantially in register with the outlet ports 85, 86, 87, 88, 89 and 90 in the casing 82; with ports 91a and 101a substantially in register with the outlet ports 91 and 101 of the casing; and with ports 102a and 103a substantially in register with the inlet ports 102 and 103 in the casing.

At the outside of the sleeve 108, the port 91a connects with a groove 109 which extends in a counterclockwise direction, as viewed from above, around the sleeve to a point almost directly beneath the port 8911 and then extends downwardly to a point midway between the levels of the ports 91a and 101a, where it communicates with a port 110 passing through the sleeve. At the bottom of the groove there is a series of holes 111 connected with the interior of the sleeve. In a similar manner, the port 101a connects at the outer side of the sleeve 108 with a groove 112 extending around the sleeve to a point opposite the interval between the ports 85a and 86a and then upwardly to connect with a port 113 at the same general level as port 110, the groove 112 communicating with one or more small ports 114 connecting the bottom of the groove with the inner side of the sleeve.

The rotary part or rotor 78 is preferably in a single piece fitting closely in the sleeve 108 and, at a level corresponding to that of the ports 102 and 103, is provided with a deep circumferential channel 115 around. a central shaft portion 116 provided with a diametrical bore 117 communicating with an upwardly extending vertical bore or passage 118. This bore 118 is preferably made from the top and the upper end is closed later as by means of a plug 119. To supply air to the ducts leading from the control device, provision may be made of a longitudinal groove 120 at the cylindrical outer surface of the rotor or plug and one or more radial ducts or bores 121 connecting the groove with the axial bore 118. It should be understood that the groove 120 must be of sufiicient length to extend from the upper parts of the ports 85a, 86a, 87a, 88a, 89a and 90a to the lower part of the port 101a.

Provision must also be made for venting or exhausting the air in the various ducts leading from the control. For the upper ducts this may be done by means of a circumferential groove 122 (Fig. 8) at a level corresponding to that of the upper ports 85a, 86a, 87a, 88a, 89a and 90a and radial bores 123, 124 and 125 connecting this groove with longitudinal exhaust bores 126, 127 and 128, respectively. This groove 122 is of sufficient length to vent all of these ports at one time and comes so close to the longitudinal groove 120 at opposite sides thereof that, when any one of these ports is connected with the air-supply groove 120, all or" the others will be connected with the circumferential exhaust groove 122. The exhaust bores extend to the upper end of the rotary member 78.

The exhaust of air from the lines connected with the ports 91a and 101a is effected through ports 110 and 113 (Fig. 6) located at a level midway between the levels of the ports 91a and 1010., and through a circumferential groove 129 (Fig. 9) communicating with exhaust bores 127 and 128.

The casing 62, distributing sleeve 108 and rotor 78 are supported in proper relative position by an annular member 130 supported in turn on the horizontal portion of the frame 18. The casing 82 is closed at its top by a cover 131 having an exhaust opening 132.

Admission of compressed air to one end or the other of one of the cylinders 45 and 45a would tend to throw the corresponding slide or closure member 35 from one position to the other too quickly and cause damage due to the momentum thus acquired. To avoid this disadvantage each of the lines 49, 50, 49a and 5011 may be provided with an exhaust-retarding valve 133 which will offer substantially no resistance to the admission of air to the cylinder but will retard outward movement of the air.

The operation of the apparatus is substantially as follows:

Let it be assumed that compressed air is being supplied through the pipe 13 to blow out of the machine material fed to the air current by the feed wheel 22 which is operated by the air motor 61 receiving air from a duct 104 connected with the pipe 13, and that air is being supplied to the chamber 115 in the lower part of the rotor 78 of the control device 62, the rotor being driven by said air motor. As shown in Fig. 8, the vertical supply groove 120 of the rotor has passed the port 90a where it acted to supply air to the line 49 and thereby open the upper door 35, and has acted through port 101a and line or duct 92a to prevent the passage of air from the lower chamber 10 through the duct 96a.

As the rotor continues its movement, the supply groove 120 passes subsidiary ports 114 and through these, groove 112 and port 113 keeps up the supply of air through port 101a. until the supply groove. 120 passes the port 113 and the exhaust groove 129 reaches the port 113 and exhausts the air from line 92a,.and connects the two chambers through duct 96a. Just before reaching the port 113, t esupply groove 120, has passed the ,port 85a and closed the upper :door 35, and justafter passing the port 113 the groove cooperates with the port 91a to close the exhaust or ventdevice 95 for the upper chamber, this action being continued by supplying air through, a plurality of secondary. ports 111 and port 110, all connected with groove 109. Air from the supply groove is supplied to the port 91a slightly before the end of the exhaust groove 129 ,reaches the port 113 to open the device 95a and connect the upper andlower chambers to equalize the pressure therein, this .opening following closely the closing of the exhaust or vent device 95. 7,

,After passing the port 9.1a, the supply groove 120.reaches the port 86a through which and the duct 59 the air passes toand through the arm .39 to raise the door .35 against the sealing ring .39 where it will tend to be held by the air pressure in the correspondingchamber. When the supply groove 120 reaches the port 37a, air will be admitted through duct 49a to the .head end of the cylinder a, thereby opening the lower door 35d. This door will remain open until the supply groove reaches the port 38a, through which and the line or duct 50a. air is supplied to the piston ,rod end of the cylinder 45a to move the lower doorto closed position.

As the supply groove 12.0 passes the port89a, air is supplied through duct 59a to raise the lower door to sealingposition. At substantially the same time, the exhaust groove or channel 129 (Fig. 9) reaches .port 110 connected with port "91a and Iexhauststhe line 92 to vent the upper chamber, and the groove 120 reaches the port 101a to shut off communication between the two chambers through duct 96a. Finally the groove 1'20 reaches the port a and the air passes through duct 49 to the head end of cylinder 45 to move door 35 to open position, thus completing one cycle of operation. Inasmuch as the air at one end of each cylinder is at substantially at atmospheric pressure when air is admitted at the other end, there would tend. to be too fast movement of the corresponding door, thus rendering it difficult 'to stop the same at the end of its movement. All trouble of this kind is, however, avoided by use of the retarding devices 133,

Although compressed air has been referred to throughout the description, it should be understood that any other suitable elastic fluid may be used.

By backfilling in mines is meant the replacing by waste material and the like ofvaluable material, suchas coal, which has been removed, the Waste material being packed ,as tightly as practicable in the spaces left empty .by the mining operation. The principal purpose of such backfillingis to avoid subsidence or squeezes, ,and this operation provides practically the only means by which coal can be mined without loss under pop- ,ulated areas. Heretofore most of such backfilling ,has been hydraulic but this method has many disadvantages which arise principally from the large volume of water required, ,difiiculty in disposingof the water thus discharged in the mine, the expense of pumping the waste water tothe surface. Obviously, when compressed air is used the discharged air takes care of itself.

It should be understood that various changes may be made in the construction and arrangement of parts and that various features may be used without others without departing from the true spirit and scope of the invention.

Having thus described my invention, Iclaim:

1. In backfilling apparatus and the like for transporting loose material by a current of compressed air, .a chamber having an opening at its top to admit material to the chamber, a door to close said opening from below, means including a cylinder and an air-actuated piston to movesaid door to and. from closing position, air-actuated means to lift said door vertically from closing position to a position to seal said for venting said chamber, compressed air means for controlling the chamber venting means, means for supplying air under pressure to said chamber, means for discharging material from said chamber, means acting in sequence to open said venting means, admit compressed :air into one end of the cylinder to move the door away from closing position, admit air to the other end of the cylinder to return the door to closing position, admit air to the means for lifting the door to scaling position, close said venting means through the compressed air controlling means therefor, supply air under pressure to said chamber, and discharge material from the chamber, andexhaust-retarding means to retard the movement of said door by said piston, said means acting in sequence including a valve having a rotating member whereby all of such sequential operations are produced.

-2. In backfilling apparatus and the like for transporting loose material by a current of compressed air; the combination of two superposed chambers, a tight-fitting door at the top of the upper chamber movable to admit loose material into such chamber, a tight-fitting door between said chambers :to control movement of material from the .upper chamber tothe lower, means to feed material from the bottom of the lower chamber into said current, a vent for the upper chamber, a second connection between said chambers, and means for effecting in regular sequence-opening of the vent to reduce the pressure in the upper chamber to atmospheric pressure, opening of the door at the top of the upperchamber to admit a charge of loose material, closing of door at the top of the upper chamber, closing the vent, opening said second connection to bring the pressure in the upper chamber up to that in the lower chamber, openingthe door between the chambers to discharge material .from the upper chamber to the lower, closing the second connection, and closing the door between the chambers, said means for effecting' operations in regular sequence including a valve having a rotating member whereby all of such sequential steps are produced.

3.111 backfilling apparatus and the like for transporting loose material by a high pressure air current, a chamber having openings at its top and bottom; an upper door to close the upper opening from below, a lower door to close the lower opening, air actuated means to move said upper door in a generally horizontal direction toward and from closing position beneath the upper opening, means for discharging air from said chamber to reduce the pressure before opening the door, such air-discharging means includes a tubularidevice comprising two aligned communicating cylinders of which the upper is larger than the lower and communicates at its side with a discharge opening and at its top with the interior of the chamber through a reduced opening providing a valve seat therearound, a valve piston in the upper cylinder to engage said valve seat when raised and to expose said discharge opening when lowered, a piston in said lower cylinder connected with the upper piston and an air connection with the lower end of the lower cylinder to supply air to raise the lower piston and move the upper piston into engagement with said valve seat; and air-control means for discharging air from said chamber to lower the pressure therein, open the door, close the door and close the discharge.

4. In backfilling apparatus and the like for transporting loose material by a high pressure air current, an upper chamber, a lower chamber, an upper door to close the top of the upper chamber, a lower door to separate the upper chamber from the lower, a feed wheel beneath the lower chamber provided with pockets, an air supply pipe having a downwardly directed outlet beneath which said pockets pass in succession, a discharge pipe having one end at the lower side of said feed wheel beneath the outlet of the air-supply pipe, a vent for the upper chamber and a vent-closing device including an air duct, a connection between the chambers and a connection-closing device including an air duct, an operating device for each of said doors including a duct through which air is supplied to open the door and a duct through which air is supplied to close the door, an air control connected with all of said ducts to operate the corresponding devices in the desired timed relation and including a rotary member, an air motor for operating said feed wheel, and a one-way con nection between the motor and the rotary member to operate the control and operate the aircontrolled parts in suitable order.

5. In backfilling apparatus and the like for transporting loose material by a high pressure air current, an upper chamber, a lower chamber, an upper door to close the top of the upper chamber, a lower door to separate the upper chamber from the lower, a feed wheel beneath the lower chamber provided with pockets,

I an air pipe having a downwardly directed outlet beneath which said pockets pass in succession, a discharge pipe having one end at the lower side of said feed wheel beneath the outlet of the air-supply pipe, a vent for the upper chamber and vent-closing means including an air duct, a connection between the chambers and connection-closing means including an air duct, an operating device for each of said doors including a duct through which air is supplied to open the door and a duct through which air is supplied to close the door, an air motor for operating said feed wheel, and an air control including a stationary portion having ports to which said ducts are connected and a rotary part inside said stationary portion operated by said motor and having a longitudinal air-supply passage, one or more longitudinal exhaust passages, a longitudinal air supply groove at its surface connected with said air-supply passage and adapted for connection with said ports, and one or more circumferential exhaust grooves connected with said exhaust passages and adapt ed for connection with said ports.

6. In backfilling apparatus and the like for transporting loose material by a high pressure air current, an upper chamber, a lower chairiber, an upper door to close the top of the upper chamber, a lower door to separate the upper chamber from the lower, a feed wheel beneath the lower chamber provided with pockets, an air pipe having a downwardly directed outlet beneath which said pockets pass in succession, a discharge pipe having one end at the lower side of said feed wheel beneath the outlet of the air-supply pipe, a vent for the upper chamher and vent-closing means including an air duct, a connection between the chambers and connection-closing means including an air duct, operating means for each of said doors including a duct through which air is supplied to open the door, a duct through which air is admitted to close the door and a duct through which air is admitted to seal the door, an air motor for operating said feed wheel, and an air control including a stationary portion having near its top six ports arranged in two opposite sets of three connected in order with the upper-doorclosing duct, the upper-door-sealing duct, the duct for closing the vent of the upper chamber, the lower-door-opening duct, the lower-doorclosing duct, the lower-door-sealing duct and the upper-door-opening duct, a port connected with the vent-closing duct for the upper chamber between the door-closing and door-sealing ducts for the upper door and at a lower level, a port at a lower level connected with the vent-closing duct for the lower chamber positioned beneath the interval between the upper door closing and sealing ports, each of the ports for the ventclosing ducts being connected with a groove extending substantially in a counterclockwise direction to a position adjacent to that of the other port and then extending to a level midway between the corresponding ports, and a rotary member driven by said motor in a counterclockwise direction having vertical internal air supply and exhaust passages, a longitudinal air supply groove connected with an air supply passage adapted to communicate with all of said ports, a horizontal exhaust groove at the level of said upper ports terminating at opposite sides of the supply groove and connected with an exhaust passage, a second horizontal exhaust groove connected with an exhaust passage adapted to communicate with offset ends of grooves connected with the vent-controlling ports.

7. In backfilling apparatus and the like, an upper chamber, an upper door at the top of the chamber, a vent for the upper chamber, a lower chamber, a lower door between the upper lower chambers, a vent for the lower chamber discharging into the upper chamber, a compressed air line for transporting loose material, means for feeding material from said lower chamber into said air line, and means for feeding material through said upper chamber to said lower chamber including for each door a duct transmitting air to open the door, a duct through which the door is closed and a duct through which the door is sealed, and for each vent a duct supplying air to close the same, and an air control for said ducts including an outer casing having at one level six door-controlling ports connected with the corresponding ducts, one vent controlling port at one level connected with the corresponding duct and the second vent-controlling port at another level connected with the corresponding duct, a distributing sleeve in said casing provided with ports registering with said norts in the casing and at its outside with a operate with all of said ports during each rotation, a circumferential groove connected with an interior discharge passage and extending at the level of the door controlling ports almost to the opposite sides of the longitudinal groove, and a circumferential exhaust groove extending substantially one-third of the distance around the rotary member at the level of the exhaust ports in the offsets of the grooves in the distributing sleeve.

GEORG DOMINA. 

